Vania



WTED STATES Parana rice.

JOSEPH BECKER, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE KOPPERS COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYL- particularly in the electrochemical industry,

on account of the low percentage of mineral impurities that it contains. Heretofore, the manufacture of this class of coke (commonly known as .pitch coke) has been a matter of considerable difiiculty due partly to the liquid nature of the bituminous material when fused. Such processes have required 7 the use of iron retorts or stills of special character. Furthermore, in order to expel the requisite proportions of volatile matter to produce a useful coke, such vessels have to be heated to such a high temperature that' they rapidly deteriorate. Even under the most favorable conditions, the resulting coke contains a considerable percentage of volatile matter, some typical examples showing from five to seven percent. of such matter. This renders the coke unfit for use for oer.- tain purposes, without being first calcined at high temperatures. Previous attempts to manufacture pitch cokes at high temperatures in byproduct coke ovens or retorts' made of fireclay or other non-metallic refractory'material have failed for two par-' ticular reasons.

1st. If'the oven or retort is maintained at a high temperature and a charge of pitch is introduced, thecharge boils and intumesces violently and much of it is likely to be expelled through the chargin ports or oil'- takes. Such apparatus is, in act, not adapted to handle liquid or liquefiable material.

2d. If, on the other hand, the oven or retort is charged cold, then heated .to a high temperatureto make the coke, then emptied and cooled to receive a second charge, and so on, the successive alternating heating and cooling operatlons inevitably produce serious cracks which in a short-time render the apparatus useless.

Patented Nov. 4, 1919.

VANIA.

v MANUFACTURE OF COKE.

1 320 371. Specification of Letters Patent.

No Drawing.

Application filed March 15, 1918. Serial No. 222,584.

Even where iron vessels are employed, the material when finally coked tends to adhere very closely to the walls and bottom of the retort, making it diflicult to remove.

My invention is designed to avoid all these difliculties and to provide a practical and efficient method of making coke from fusible bituminous materials which can be carried out in coke ovens or gas retorts of any standard types used in the art. My invention also provides a cyclic process for the commercial manufacture of coke from liquefiable bitu-. minous materials of a very low-ash content.

My invention is based upon the discovery that if the fusible bituminous material is mixed in proper proportions with an artificial carbon, and then subjected to coking heating, and then a proportion of the product is mixed with such fusible bituminous material and the mixture subjected to coking heating; and'a proportion of the new product is in turn similarly mixed and treated, and so on the mixture so formed will have coking properties, the process of manufacture can be readily carried out without the difliculties above referred to, the gases generated by the coking operation can be treated for the recovery of valuable byproducts, and said gases, either before or after recovery of byproducts, may be utilized as the heating medium, in whole or part, for the coking operation. In this cyclic process, each coking charge consists only of crushed coke previously formed from a similar mixture, and liquid bituminous material (and the most important materials for the industrial manufacture of low-ash coke." It is to be understood, however, that my invention may be successfully applied to any liquefieach charge.

able bituminou material of the nature of pitch, whether such material is initially in liquid or semiliquid o-r solid form.

In the practice of my invention, I first mix the pitch with a quantity of crushed or ground artificial carbon, such as crushed 'coke. In practice, it is preferable to crush or grind both the carbon and pitch to a size such that it will pass through a screen of one-fourth inch mesh, but larger size material may be used, depending upon the quality of the product desired. The more finely the carbon i crushed, the firmer and more uniform will be the product. I have obtained good results for large scale work by mixing thirty to fifty per cent. of ground pitch with seventy to fifty per cent. of ground coke. I place this mixture in a coke oven or gas retort of any standard type used in the art, heated to a high temperature. The charge is allowed to remain in the oven or retort until the volatile matter is expelled and the residue is coked to a satisfactory degree. Usually it is desirable to continue the heating until the residue contains less than one per cent. of volatile material, but for certain purposes a larger percentage of such volatile matter is allowable.

The proportion of bituminous material may be easily regulated by a few trials. It is ordinarily advantageous to use the maximum amount that the coke is capable of con-' taining without having an excess that will boil out too rapidly or form masses of spongy residues. When the right proportion of pitch, is employed, a massive compact-product is formed. i The mixture with the coke very greatly increases the internal friction or viscosity of the charge, resulting in a pasty mass which can be readily coked and does not tend to separate. The method is thus carried forward in a cyclic manner (the coke employed in eachacharge being coke produced in'a previous charge made from the same or similar material. Thus, in making a pitchcoke, I make a mixture such as above described, consisting of about thirty per cent. of ground pitch mixed with selenty per cent. of ground coke, previously produced from the same or similar material. Twvelve'tons of such material are charged into a coke oven and about ten and one-fourth tons of coke may be recovered from this, charge. After the coking operation is completed, the oven or I retort is emptied, the coke is cooled with water or otherwise, and about eight and one-fourth tons of the coke are ground or crushed and mixed with about three and sixtenth tons of pitch for a new charge, leaving a surplus of about two tons of coke from Thus, each charge produces enough coke for use in a subsequent charge, with a surplus over for commercial purposes. I have found the best results are obprogresses and acts as a cooling agent which prevents the material in the interior of the oven or retort from becoming too fluid.

The oven or retort may be equipped with an offtake pipe and with apparatus of any usual or suitable character forrecovering the gases, oils, ammonia, etc., and the advantage of my invention is that it permits the use of standard apparatus and methods for this purpose. The gases passing off from the oven or retort usually contain a high percentage of hydrogen and hydrocarbons, and such gases may be. used to advantage for heating the oven or retort, either before or after the byproducts have been recovered therefrom, thus enabling the operations to be carried on with a great economy of fuel.

The term pitch is used in the appended claims in a generic rather than a technically specific sense, and to include ebulliently liquefiable bituminous materials of the general nature of pitch; and my invention includes the treatment of suc produce a. substantially ash-free coke and yet remedythe coking difliculties hereinabove indicated.

While I have herein described what I now believe to be the preferred manner of carrying'out my invention, it will be obvious to those skilled in the art that various changes and modifications may be made in carrying out the process, without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

- 1. In a method of coking pitch: making crushed coke derived from such a coked secondary mixture, and then cyclically repeat-' ing such course, whereby the successive cokings yield a surplus of substantially ash-free coke derived substantially from pitch alone.

2. In a method of coking-pitch: making and coking a primary mixture of pitch with coke derived directly from coal, then making and coking a secondary mixture of pitch with coke derived fromsuch a coked primaterials to v mary mixture, then making and coking a tertiary mixture of pitch with coke derived from such a coked secondary mixture, and then cyclically repeating such course, whereby the successive cokings yield a surplus of substantially ash-free coke derived substantially from pitch alone.

3. In a method of coking pitch: making and coking a primary mixture of crushed ings yield a surplus of substantially ash-free v coke derived substantially from pitch alone.

4:. In a method of coking pitch: making and coking a primary mixture of pitch with coke having a substantial ash-content, then making and coking a secondary mixture of pitch with coke derived from such a coked primary mixture, then making and coking a tertiary mixtureof pitch with coke derived from'such a coked secondary mixture, and then cyclically repeating such course, whereby the successive cokings yield a surplus of substantially ash-free coke derived substantially from pitch alone.

5. In a method of coking pitch: making and coking'a primary mixture of crushed pitch with crushed coke, then making and coking a secondary mixture of crushed pitch with crushed coke derived from such a coked primary mixture, then making and coking a tertiary mixture of crushed pitch I with crushed coke derived from such a coked secondary mixture, and then cyclically repeating such course, whereby the successive cokings yield a surplus of substantially ash-free coke derived substantially from pitch alone.

6. In a-method of coking pitch: making and coking a primary mixture of pitch with coke, then making and coking a secondary mixture of pitch with coke derived from such a coked primary mixture, then making and coking" a tertiary mixture of pitch with coke derived from such a coked mixture, and then cyclically repeating such course whereby the successive cokings yield a surplus of substantially ash-free coke derived substantially from pitch alone.

7. In a method of cokingp-itch: making and coking a primary mixture of not over about 70% of pitch with not under about 30% of coke, then making and coking asecondary'mixture, in like proportion, of pitch with coke derived from such a coked primary mixture, then making and coking a tertiary mixture, in like proportion, of pitch with coke derived from such a coked secondary mixture, and then cyclically repeating such course, whereby the successive cokings yield a surplus of substantially ash-free coke derived substantially from pitch alone.

8. In a method of coking pitch: making and coking a'primary mixture of pitch with coke, and then cyclically repeating such step,

utilizing in such cyclic repetition coke derived from such a coked mixture, whereby the successive cokings yield a surplus of substantially ash-free coke derived substantially from pitch alone. I

In testimony whereof, I have hereunto set my hand.

JOSEPH BECKER. 

